Investigation of the microstructure of the heat-affected zone of low-alloyed steel during pulsed arc aelding under conditions of low climatic ambient temperatures

Abstract

Abstract The development of a special technology of welding at low temperatures is an urgent scientific and technical challenge aimed at solving the problems of increasing the reliability and safety of products of equipment and structures operated under conditions of the North and the Arctic. One of the perspective technologies is pulsed arc welding. The structure of the heat- affected zones (HAZ) of welded joints produced by pulsed arc welding at an ambient temperature of 45 degrees Celsius below zero was studied. Two frequency modes were applied during modulated-current welding, and the results obtained were compared with the traditional method of manual arc welding with direct current. The features of the influence of the modulation frequency of the welding current and the temperature of the welding performance on the microstructure of the HAZ of 09G2S steel welded joints are revealed.